Fix warning "passing argument from incompatible pointer type".

Patch by Eli Friedman, eli d friedman a gmail

Originally committed as revision 24020 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/nutdec.c

@@ -95,7 +95,7 @@ static int get_packetheader(NUTContext *nut, ByteIOContext *bc, int calculate_ch
 //    start= url_ftell(bc) - 8;
 
     startcode= be2me_64(startcode);
-    startcode= ff_crc04C11DB7_update(0, &startcode, 8);
+    startcode= ff_crc04C11DB7_update(0, (uint8_t*)&startcode, 8);
 
     init_checksum(bc, ff_crc04C11DB7_update, startcode);
     size= ff_get_v(bc);